Bolt for use with resin clips

Abstract

Disclosed is a stud bolt having nonsymmetrical screw threads projecting from the shank thereof, wherein each screw thread of the stud bolt has an inwardly concave curved flank and an outwardly convex curved flank. With this arrangement, the load required to fit a resin clip over the stud bolt can be lowered below that needed for a conventional stud bolt while maintaining the load required to remove the clip equal to or more than that for the conventional bolt. Thus, this stud bolt allows a resin clip to be easily fitted over the bolt.

What is claimed is: 
     
       1. A stud bolt, comprising: a stud welding portion;   a shank portion, attached to the stud welding portion; and   screw threads formed on the shank, wherein the screw threads have a convex, curved surface facing away from the stud welding portion, and a concave, curved surface facing toward the stud welding portion, such that the convex and concave surfaces converge and meet to form a single common thread crest.     
     
     
       2. A bolt according to claim 1, wherein an angle between a plane perpendicular to a central axis of the shank and a line passing through the single common thread crest and a point of intersection of a root of the screw threads and each curved surface, is 15° on a side of the threads facing the stud welding portion and 45° on a side of the threads facing away from the stud welding portion. 
     
     
       3. A bolt according to claim 1, wherein the convex and concave surfaces of the threads are nonsymmetrical with respect to a plane perpendicular to an axis of the shank of the bolt which passes through the single common thread crest.